The need for improvements in lead-acid storage batteries is widely recognized.
Hundreds of articles, patents and research projects have been directed toward improving such batteries. Some of the important characteristics that still need improvement are mechanical ruggedness, long life and multiple cycles (charge-discharge).
It is generally believed that automobile batteries have a lifetime of 3, or at most 6, years and that to have longer life they should have thicker lead positive grids. In contrast, the present invention intends to provide a 10 year lifetime battery using thinner grids.
ADAC 2008 for the year 2007 states “The battery remains a weak link . . . breakdowns on 1.95 million vehicles six years or less are as follows: 52% battery . . . breakdown due to the battery remains the number one cause.”
According to “Wikipedia” “Because of vibration, shock, heat, cold, and sulfation of their lead plates, few automotive batteries last beyond six years of regular use. Automotive starting batteries have many thin plates to provide as much current as possible in a reasonably small package. In general, the thicker the plates, the longer the life of the battery. Positive grid corrosion ranks among the top 3 reasons for battery failure. According to Solarnavigation “Plate thickness (of the positive (+) plate) matters . . . so the thickest plates will last the longest”
It has been suggested that the power or lifetime of lead acid batteries may be increased by substituting lead plates (grids) with other materials. However, it is believed that almost all commercially available lead acid batteries use lead plates. There are now a number of projects that have been reported to use non-metal battery plates. Firefly Energy has announced it is developing carbon foam plates, see U.S. Pat. Nos. 6,979,513 and 7,033,703. Also, Jung et al have filed patent applications on carbon battery plates, see U.S. application Ser. Nos. 11/048,104 and 11/279,103 (both now abandoned).
One suggestion is to use lead electroplating on a core of another metal, such as aluminum, copper, steel or titanium. Some of the prior patents and articles about lead-plated cores, or otherwise relevant, are set forth below. All of these patents and articles, and all others cited in this patent application, are included herein by reference. A series of patents to Rubin uses expanded titanium or titanium alloy positive grids without a lead coating. In U.S. Pat. No. 3,486,940 Rubin discloses a titanium nitride core with a gold covering layer; in U.S. Pat. No. 3,615,831 he discloses a similar gold covering layer over a titanium-molybdenum-zirconium alloy core and in U.S. Pat. No. 4,251,608 he discloses a steel or titanium core with a graphite protective coating. See also Rubin U.S. Pat. Nos. 3,798,070 and 3,870,563 and Will U.S. Pat. No. 4,326,017.
Lead is plated on copper in Senoo U.S. Pat. No. 5,223,354; Senoo U.S. Pat. No. 5,093,970; Nann U.S. Pat. No. 4,760,001 and Kiessling U.S. Pat. No. 4,554,228 and Re: 33,133. U.S. Pat. No. 4,683,648 to Yeh shows a titanium core electroplated with lead. U.S. Pat. Nos. 5,379,502; 5,339,873; 5,544,681 and 5,411,821 disclose copper or steel or other materials as cores with titanium and lead layers. U.S. Pat. No. 6,316,148 to Bhardwaj discloses a battery using aluminum foil which is coated with lead. U.S. Pat. Nos. 2,739,997 and 2,713,079 to Carrick disclose aluminum plates electroplated with lead in an aqueous plating bath.
The following articles may be considered relevant: Dai et al. “Lead-plated titanium grids etc.” 41 Power Sources Conference, Jun. 14-17 (2004); Dai et al. “Corrosion of Lead Plate Titanium etc” (ref. Google); Kurisawa “Development of Positive Electrodes with Tin Oxide Coating by Applying a Sputtering Technique for Lead Acid Batteries.” Journal Power Sources 1995 (2001) 1-5, 1-9.